LIGO

LIGO (Laser Interferometer Gravitational-Wave Observatory) is a pair of massive scientific instruments designed to detect gravitational waves—ripples in the fabric of Spacetime itself. These waves, predicted by Einstein's General Relativity, are produced by cataclysmic cosmic events like colliding Black Holes or merging Neutron Stars.

Each LIGO detector uses a laser split into two perpendicular beams that bounce down 4-kilometer-long arms, then recombine. When a gravitational wave passes through, it warps Space itself, changing the arm lengths minutely. This shift alters the laser's interference pattern, producing a detectable signal.

The first confirmed gravitational wave detection in 2015—from two merging black holes 1.3 billion Light-years away—vindicated a century of theoretical prediction and earned the LIGO team the Nobel Prize in Physics. Since then, LIGO has opened an entirely new way to observe the Universe, complementing traditional telescopes and revealing cosmic events invisible to light.

Located in Washington State and Louisiana, LIGO represents one of humanity's most sensitive instruments, capable of measuring distances smaller than a proton.

Related

General Relativity, Black Holes, Neutron Stars, Gravitational Waves, Laser, Nobel Prize